Predictive factors for technically difficult endoscopic submucosal dissection in the colorectum

Because of technical difficulty, colorectal endoscopic submucosal dissection (CR-ESD) is not widely performed. We aimed to determine risk factors for such technical difficulty as defined by long procedure duration (≥  150 min), perforation, and piecemeal resection.

Patients with consecutive colorectal tumors treated with ESD between April 2006 and December 2010 were enrolled in a prospective cohort study. For prediction of technical difficulty, three types of factor were investigated: tumor location, tumor type, and colonoscopy-related. Cases were subsequently categorized into earlier and later periods (April 2006 - August 2008, 123 lesions; September 2008 - December 2010, 124 lesions). Variables were analyzed using multiple logistic regression, with subgroup analyses for each period.

247 lesions were analyzed. Flexure location was an independent risk factor for technical difficulty as measured by longer procedure duration (odds ratio [OR] 4.1, 95 % confidence interval [95 %CI] 1.1 - 14.9), piecemeal resection (4.7, 1.1 - 17.2), or perforation (8.8, 1.1 - 56.8). Tumor with scarring or locally recurrent was a risk factor for longer procedure duration (4.7, 1.7 - 13.7), and for piecemeal resection (7.8, 2.4 - 25.0). Tumor of size  ≥  50 mm or spreading across ≥  2 folds was the strongest independent risk factor for longer duration (6.3, 2.8 - 15.4), and was an independent risk factor for longer duration in both time periods (earlier, 3.3, 1.1 - 10.4; later, 27.4, 7.4 - 138.0). Flexure location was an independent risk factor for perforation (13.9, 1.5 - 129.1) and for piecemeal resection (5.1, 0.9 - 25.2) in the earlier but not the later period.

Factors predicting technical difficulty of CR-ESDs were clarified. Their importance was influenced by the increasing experience of the endoscopist.